World CO2 emissions 
from energy 
CO2 emissions by nation
CO2 emissions by nation per capita.
This data from the US EPA gives an idea of the relative industrial nation
​ contribution to CO2 emissions from fossil fuels. 
For zero carbon emissions all CO2 sources matter.

Fossil fuel combustion  Industry, building, transport​. This includes natural gas, which is mainly methane. Though burning natural gas releases about half the CO2 of coal, methane fugitive emissions (leaks) makes natural gas almost as bad as coal (2018 research). 

Cement manufacture (burning limestone)
Deforestation (mainly for livestock)

Food production/agriculture (disturbing soil releases CO2)

Carbon feed backs(caused by global warming) 

Combustion of ​​
 Illustrations showing  CO2
​ emissions sources
Sources of CO2
Carbon emissions from deforestation and industrial food production 
Methane atmospheric
​ oxidation to CO2
Sources by industry

C​arbon dioxide emissions by national quantities
Industrial scale deforestation is a major source of carbon dioxide.
​Most of the deforestation goes towards the raising of livestock.
This makes industrial food production a major source of carbon dioxide and methane​.
CO2 sources
The original source of fossil carbon fuels goes back 300 million years.